The energy capable of coming out of the front aperture of the device.
| Class 4 | >500mW | Unsafe for eye Unsafe for skin |
| Class 3B | <500mW | Unsafe for eye Unsafe for skin |
| Class 3R | <5mW | Generally safe for eye and skin under special conditions |
| Class 2M | <= 1mW | Safe for eye, but unsafe with viewing aids Safe for skin |
| Class 2 | <= 1mW | Safe with (0.25s) aversion response including viewing aids Safe for skin |
| Class 1M | <=0.4mW | Safe for eye, but unsafe with viewing aids Safe for skin |
| Class 1 | <=0.4mW | No precautions required |
